Calcium-mediated rapid movements defend against herbivorous insects in Mimosa pudica.

Animals possess specialized systems, e.g., neuromuscular systems, to sense the environment and then move their bodies quickly in response. Mimosa pudica, the sensitive plant, moves its leaves within seconds in response to external stimuli; e.g., touch or wounding. However, neither the plant-wide signaling network that triggers these rapid movements nor the physiological roles of the movements themselves have been determined. Here by simultaneous recording of cytosolic Ca 2+ and electrical signals, we show that rapid changes in Ca 2+ coupled with action and variation potentials trigger rapid movements in wounded M. pudica. Furthermore, pharmacological manipulation of cytosolic Ca 2+ dynamics and CRISPR-Cas9 genome editing technology revealed that an immotile M. pudica is more vulnerable to attacks by herbivorous insects. Our findings provide evidence that rapid movements based on propagating Ca 2+ and electrical signals protect this plant from insect attacks.